Do note that the part you wish to make a flat pattern of has to be a sheet metal part. If it's not, you can use the 'convert to sheet metal' button somewhere in there as well. (use the command finder if you can't find it).
NX 7.5.5.4 with Teamcenter 8 on win7 64
Intel Xeon @3.2GHz
8GB RAM
Nvidia Quadro 2000